Tuning dial



Jan. 21, 1930. J. w. FITZGERALD 1,744,265

TUNING DIAL Filed March 14-, 1929 al-- 15 127mm? 7/27/77 lff imzY/figav/h 23y QMWW Patented Jan. 21, 1930 UNITED STATES PATENT OFFICEJOHN W. FITZ GERALD, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO BRIGGS &STRAT- TON CORPORATION, OF MILWAUKEE, WISCONSIN, A CORPORATION OFDELAWARE TUNING DIAL usauu) Application filed March 14, 1929. Serial No.347,036.

This invention relates to certain new and useful improvements in radiotuning dials.

Heretofore, the dials which have been used to control the tuningelements of radio re- 1ceivers were manually actuated, and were'provided with suitable delineations adjacent their periphery, withwhich a stationary marker carried by the panel cooperate-d to enable theoperator to adjust the dial, and m consequently the receiver to adesired frequency. However, this method required considerable patienceand therefore automatic tuning devices were developed which enabled theoperator to adjust the receiver to a desire-d broadcasting station bymerely pressing a button.

Such automatic controls, however, were complicated and necessitatedconsiderable change in the design of the receiver with which they wereused.

It is, therefore, an object of this invention to provide an improvedtuning dial for radio receivers and the like which may be quicklyattached to any standard receiver without in any way altering its designor construction, and which is provided withvmeans by which the operatoris enabled to quickly move the dial to adjust the receiver to any ofseveral predetermined frequencies.

Another object of this invention resides in the provision of an improvedconstruction for radio tuning dials and the like which embodies thedesirable features of an automatic control. 7

And a further object of this invention resides in the provision of animproved radio tuning dial and the like, which is provided with aplurality of buttons or indicating devices, which may be individuallymoved to an operative position, whereby rotation of the ed claims, itbeing understood that such changes in the precise embodiment of theherein disclosed'invention mar be made as come within the scope ofthe caims.

In the accompanying drawing, 1' have illustrated one complete example ofthe physical embodiment of my invention constructed according to thebest mode I have so far devised for the practical application of theprinciples thereof, and in which:

Figure 1 is an elevational View of a radio receiver dial embodying myinvention;

Figure 2 is a cross sectional view taken through Figure 1 on the planeof the line 2-2; 1 v

Figure 3 is a cross sectional view taken through Figure 2 on the planeof the line 33 and illustrating the back of the dial, and

Figure is a perspective view of the fixed stop which coo crates withadjustable stops cirried by the ial, to arrest movement there- 0Referring now more particularly to the accompanying drawing in whichlike numerals designate like parts throughout the several views, thenumeral 5 represents the panel of a radio receiver, not shown, whichusually includes one or more tuning elements for tuning the receiver toa desired frequency, and

whose shaft 6 projects through an opening 7 in the panel to have asuitable actuating dial secured thereto.

In the present invention a dial 8 preferably formed of insulatingmaterial, such as a phenol condensation product, is secured to the shaft6 by a set screw 9 or the like and has the back of its major portionrecessed, as at 10, for a purpose to be later described.

Surrounding the usual central knob 11 are a plurality of indicatingdevices or buttons 12 which are adapted to havethe call letters of anumber of desired broadcastin stations displayed thereon, the indicatingevices or buttons 12 being depressible into the dial recess 10 to anoperative position, whereupon rotation of the dial is arrested at apredetermined point, and the receiver tuned to the particularbroadcasting station designated on Ophe indicating device or button soactuate 1 The buttons 12, each consists of a threaded stud 13 whose head14 is externally threaded to receive a retaining shell 15 in which apaper or other suitable disc 16, upon which the station call letters aredelineated, is positioned. The stud 13 is threaded in a sleeve 17 fixedto a segment 18 of a spring member 19 secured to the dial within itsrecess in a manner to be later described. The innermost end of the stud13 has a stop member 20 fixed thereto, which consists substantially of alever projected from the stud and whose outermost end is directedlaterally to provide the stop proper. Depression of the button flexesthe segment 18 of the spring member 19, as clearly illustrated in thelower half of Figure 2 and moves the stud and consequently the stop 20into the path of a stationary stop member 21 fixed to the panel.

The stationary stop 21 is struck from bendable metal and has a centralaperture 22 through which the shaft 6 extends, and diametrically opposedarms 23, the outer ends of which have laterally extended portions 24which provide a pair of stationary stops with which the stops 20 carriedby the indicating buttons are engageable, a screw 25 maintaining themember 21 in proper fixed position. Threading of the stud 18 into thesleeve 17 permits longitudinal adjustment of its stop, so that it willnormally pass over the laterally projected portions 24 of the stop 21.

The spring member 19 is secured to the face of the recess 10 in the dialby having a portion of the metal hub 26 of the dial swedged, as at 28,over it and a washer 27 positioned outwardly of the member 19 tostrengthen the same. The natural tendency of the spring member 19 is tomaintain itsseveral segments, to which the indicating buttons are fixed,in

flat alignment, so that the stops 20 are nor mally held out of the pathof the projections 24 0 tion of the dial, as will be readily apparent.

The radial position of the stops 20 permits them to be adjusted withrespect to the rotation of the dial, to arrest the movement thereof atthe proper point; the adjustment being accomplished by merely turningthe indicating buttons and locking them against further rotation bysuitable lock nuts 29.

' The usual radio receiver is so designed that the shaft of its tuningelements revolves through 180 degrees, and therefore the pro-v vision ofstop buttons entirely around the dial provides stops for stations whosefrequencies are comparatively close to each other. This advantage isillustrated in Figure 1, ..i-n which one stop button 12 is arranged toarrest the movement of the dial to tune the receiver to the broadcastingstation W. G. N. and its adjacent button is arranged to stop the tuningelement of the receiver at the frequency of the station W. M. A. Q.

The broadcasting station W. L. W. op-

the stationary stop to permit free rota-' erates on a frequency betweenW. G. N. and W. M. A. Q., and as there are no indicating buttons betweenthe two, which have been adjusted to the stations W. G. N. and W. M. A.Q, the button diametrically opposite that of W. G. N. is utilized tocontrol the receiver when it is desired to tune the same to thebroadcasting station W. L. W., the stop 20 of this latter buttoncooperating with the lowermost projection 24 of the fixed stop 21. In asimilar manner, the remaining buttons may be adjusted to desiredbroadcasting stations.

From the foregoing description taken in connection with the accompanyingdrawing, it will be readily apparent to those skilled in the art towhich an invention of the character described appertains, that I providean improveddial for radio receivers and the like, which obtains in asingle unitary device, the advantages of a complicated automaticcontrol, without in any way complicating the design of the receiver, andat an extremely low cost.

What I claim as my invention is '1. In a control for radio receivers andthe like, a control member having uninterrupted manual movement,indicating means adapted to be moved to an operative position, and stopmeans cooperating with said indicating means whereby movement of thecontrol after the indicating means is moved to an operative position isarrested at a predetermined point.

2. In a control of the character described, a stationary stop, a movablestop adapted to be moved into the path of the stationary stop wherebymovement of the control may be arrested at a predetermined point, andmeans normally holding the movable stop out of the path of thestationary stop.

3. In combination with a control for radio receivers and the like, astationary stop, a movable stop normally out of engagement with thestationary stop, and means whereby the movable stop may be engaged withthe stationary stop to quickly move the control to a predeterminedposition.

4;. In combination with a radio tuning control, a stationary stop,indicating means including a stop engageable with the stationary stop toarrest the movement of the radio tuning control at a predeterminedpoint, and means normally holding the indicating stop out of engagementwith the stationary stop.

5. A tuning device of the character described comprising a normallystationary abutment, a body member, a spring member carried by the bodymember, and a stop device carried by the spring member and movableagainst the resiliency of the spring member to an operative position inthe path of the abutment.

6. The combination with a control dial of the character described, of astationary stop, a yieldable member carried by the dial, and

stop means carried by the yieldable member and movable against theresiliency of the yieldable member to engagement with the stationarystop.

7. The combination with a movably mounted control dial of the characterdescribed, of a stationary stop, yieldable means carried by the controldial, an indicating member carried by the yieldable means, and a stopcarried by the indicating member and movable into the path of thestationary stop against the resiliency of the yieldable means to arrestthe movement of the dial at a predetermined point.

8. The combination with a movably mount ed control dial of the characterdescribed, of a stationary stop, yieldable means fixed to the dial, amember having means for indicating a predetermined position of themovable mounted dial, and a stop carried by the said member and movableinto the path of the stationary member upon depression of the memberagainst the resiliency of the yieldable means, to arrest the movement ofthe dial at said predetermined point,

9. The combination with a movably mounted control dial of the characterdescribed, of a stationary member, indicating means carried by the dialincluding a stop movable into engagement with the stationary member toarrest the movement of the dial, and means whereby said stop may beadjusted to arrest the movement of the dial at a predetermined point.

10. The combination with a movably mounted control dial of the characterdescribed, of a stationary stop, a movable stop carnied by the dial andoperable to arrest the movement of the dial, and means for adjustingsaid dial carried stop with respect to the dial whereby the movement ofthe dial may be arrested at a predetermined point.

11. A control device of the character described comprising thecombination with a normally stationary abutment, of a dial adapted fornormal uninterrupted rotation, a plurality of predetermined setindicating elements mounted on the dial for movement relative theretoand into the path of the abut ment, and said elements being arranged toprovide handles to facilitate the quick rotation of the dial to thepredetermined position indicated by the indicating element so moved.

k In testimony whereof I have hereunto affixed my signature.

- JOHN W. FITZ GERALD.

